Extended relationship signaling between events in event message tracks

ABSTRACT

Systems, devices, and methods for Dynamic Adaptive Streaming over HTTP (DASH) is provided. A method includes: obtaining an event message track including a plurality of event message instance boxes, the event message track configured to be processed by a DASH client for displaying media content; obtaining a first event message instance box included in the event message track; obtaining a second event message instance box included in the event message track, wherein the second event message instance box includes first information identifying the first event message instance box, and second information specifying a relationship between the first event message instance box and the second event message instance box; modifying the first event message instance box based on the first information and the second information; and providing the event message track to the DASH client or displaying media content based on the event message track.

CROSS-REFERENCE TO THE RELATED APPLICATIONS

This application claims priority from U.S. Provisional Application No.63/177,271, filed on Apr. 20, 2021, the disclosure of which isincorporated herein by reference in its entirety.

FIELD

Embodiments of the present disclosure are directed to media streamingand, more particularly, Dynamic Adaptive Streaming over HyperTextTransfer Protocol (HTTP) (DASH).

BACKGROUND

ISO/IEC 23009-1 Dynamic Adaptive Streaming over HTTP (DASH) standardintroduced events message boxes for carrying events with media segments.Further, ISO/IEC 23001-19 CD defines an Event Message Track format,where a track can carry event messages.

The current Event Message Track specification uses a box for carryingeach event instance. The only relationship between two instances thatcan be signaled in this box is when two event instances are equivalent,i.e. processing one is adequate. However, there are more possible casesfor the relation between two event instances.

“Information technology—Coding of audiovisual objects—Part 12: ISO basemedia file format”, ISO/IEC 14496-12 (December 2015), “Draft of FDIS ofISO/IEC 23000-19 Common Media Application Format for Segmented Media”,ISO/IEC JTC1/SC29/WG11 MPEG117/16819 (April 2017); and “Text of ISO/IECFDIS 23009-1 4th edition”, ISO/IEC JTC 1/SC 29/WG 11 N18609 (August2019) are incorporated herein by reference in their entirety.

SUMMARY

In embodiments, a method performed by at least one processor includesobtaining an event message track including a plurality of event messageinstance boxes, the event message track configured to be processed by aDynamic Adaptive Streaming over HyperText Transfer Protocol (DASH)client for displaying media content; obtaining a first event messageinstance box included in the event message track; obtaining a secondevent message instance box included in the event message track, whereinthe second event message instance box includes first informationidentifying the first event message instance box, and second informationspecifying a relationship between the first event message instance boxand the second event message instance box; modifying the first eventmessage instance box based on the first information and the secondinformation; and providing the event message track to the DASH client ordisplaying media content based on the event message track.

In embodiments, a device includes at least one memory storing programcode; and at least one processor configured to read the program code andoperate as instructed by the program code, the program code including:first obtaining code configured to cause the at least one processor toobtain an event message track including a plurality of event messageinstance boxes, the event message track configured to be processed by aDynamic Adaptive Streaming over HyperText Transfer Protocol (DASH)client for displaying media content; second obtaining code configured tocause the at least one processor to obtain a first event messageinstance box included in the event message track; third obtaining codeconfigured to cause the at least one processor to obtain a second eventmessage instance box included in the event message track, wherein thesecond event message instance box includes first information identifyingthe first event message instance box, and second information specifyinga relationship between the first event message instance box and thesecond event message instance box; modifying code configured to causethe at least one processor to modify the first event message instancebox based on the first information and the second information; andproviding code configured to cause the at least one processor to providethe event message track to the DASH client or display media contentbased on the event message track.

In embodiments, a non-transitory computer-readable medium storesinstructions that, when executed by at least one processor, cause the atleast one processor to: obtain an event message track including aplurality of event message instance boxes, the event message trackconfigured to be processed by a Dynamic Adaptive Streaming overHyperText Transfer Protocol (DASH) client for displaying media content;obtain a first event message instance box included in the event messagetrack; obtain a second event message instance box included in the eventmessage track, wherein the second event message instance box includesfirst information identifying the first event message instance box, andsecond information specifying a relationship between the first eventmessage instance box and the second event message instance box; modifythe first event message instance box based on the first information andthe second information; and provide the event message track to the DASHclient or display media content based on the event message track.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features, the nature, and various advantages of the disclosedsubject matter will be more apparent from the following detaileddescription and the accompanying drawings in which:

FIG. 1 is a diagram of an environment in which methods, apparatuses andsystems described herein may be implemented, according to embodiments.

FIG. 2 is a block diagram of example components of one or more devicesof FIG. 1.

FIG. 3 is a diagram of a DASH client according to embodiments.

FIG. 4 is a diagram of a process according to embodiments.

FIG. 5 is a diagram of computer code according to embodiments.

DETAILED DESCRIPTION

FIG. 1 is a diagram of an environment 100 in which methods, apparatuses,and systems described herein may be implemented, according toembodiments. As shown in FIG. 1, the environment 100 may include a userdevice 110, a platform 120, and a network 130. Devices of theenvironment 100 may interconnect via wired connections, wirelessconnections, or a combination of wired and wireless connections.

The user device 110 includes one or more devices capable of receiving,generating, storing, processing, and/or providing information associatedwith platform 120. For example, the user device 110 may include acomputing device (e.g., a desktop computer, a laptop computer, a tabletcomputer, a handheld computer, a smart speaker, a server, etc.), amobile phone (e.g., a smart phone, a radiotelephone, etc.), a wearabledevice (e.g., a pair of smart glasses or a smart watch), or a similardevice. In some implementations, the user device 110 may receiveinformation from and/or transmit information to the platform 120.

The platform 120 includes one or more devices as described elsewhereherein. In some implementations, the platform 120 may include a cloudserver or a group of cloud servers. In some implementations, theplatform 120 may be designed to be modular such that software componentsmay be swapped in or out depending on a particular need. As such, theplatform 120 may be easily and/or quickly reconfigured for differentuses.

In some implementations, as shown, the platform 120 may be hosted in acloud computing environment 122. Notably, while implementationsdescribed herein describe the platform 120 as being hosted in the cloudcomputing environment 122, in some implementations, the platform 120 maynot be cloud-based (i.e., may be implemented outside of a cloudcomputing environment) or may be partially cloud-based.

The cloud computing environment 122 includes an environment that hoststhe platform 120. The cloud computing environment 122 may providecomputation, software, data access, storage, etc. services that do notrequire end-user (e.g., the user device 110) knowledge of a physicallocation and configuration of system(s) and/or device(s) that hosts theplatform 120. As shown, the cloud computing environment 122 may includea group of computing resources 124 (referred to collectively as“computing resources 124” and individually as “computing resource 124”).

The computing resource 124 includes one or more personal computers,workstation computers, server devices, or other types of computationand/or communication devices. In some implementations, the computingresource 124 may host the platform 120. The cloud resources may includecompute instances executing in the computing resource 124, storagedevices provided in the computing resource 124, data transfer devicesprovided by the computing resource 124, etc. In some implementations,the computing resource 124 may communicate with other computingresources 124 via wired connections, wireless connections, or acombination of wired and wireless connections.

As further shown in FIG. 1, the computing resource 124 includes a groupof cloud resources, such as one or more applications (“APPs”) 124-1, oneor more virtual machines (“VMs”) 124-2, virtualized storage (“VSs”)124-3, one or more hypervisors (“HYPs”) 124-4, or the like.

The application 124-1 includes one or more software applications thatmay be provided to or accessed by the user device 110 and/or theplatform 120. The application 124-1 may eliminate a need to install andexecute the software applications on the user device 110. For example,the application 124-1 may include software associated with the platform120 and/or any other software capable of being provided via the cloudcomputing environment 122. In some implementations, one application124-1 may send/receive information to/from one or more otherapplications 124-1, via the virtual machine 124-2.

The virtual machine 124-2 includes a software implementation of amachine (e.g., a computer) that executes programs like a physicalmachine. The virtual machine 124-2 may be either a system virtualmachine or a process virtual machine, depending upon use and degree ofcorrespondence to any real machine by the virtual machine 124-2. Asystem virtual machine may provide a complete system platform thatsupports execution of a complete operating system (“OS”). A processvirtual machine may execute a single program, and may support a singleprocess. In some implementations, the virtual machine 124-2 may executeon behalf of a user (e.g., the user device 110), and may manageinfrastructure of the cloud computing environment 122, such as datamanagement, synchronization, or long-duration data transfers.

The virtualized storage 124-3 includes one or more storage systemsand/or one or more devices that use virtualization techniques within thestorage systems or devices of the computing resource 124. In someimplementations, within the context of a storage system, types ofvirtualizations may include block virtualization and filevirtualization. Block virtualization may refer to abstraction (orseparation) of logical storage from physical storage so that the storagesystem may be accessed without regard to physical storage orheterogeneous structure. The separation may permit administrators of thestorage system flexibility in how the administrators manage storage forend users. File virtualization may eliminate dependencies between dataaccessed at a file level and a location where files are physicallystored. This may enable optimization of storage use, serverconsolidation, and/or performance of non-disruptive file migrations.

The hypervisor 124-4 may provide hardware virtualization techniques thatallow multiple operating systems (e.g., “guest operating systems”) toexecute concurrently on a host computer, such as the computing resource124. The hypervisor 124-4 may present a virtual operating platform tothe guest operating systems, and may manage the execution of the guestoperating systems. Multiple instances of a variety of operating systemsmay share virtualized hardware resources.

The network 130 includes one or more wired and/or wireless networks. Forexample, the network 130 may include a cellular network (e.g., a fifthgeneration (5G) network, a long-term evolution (LTE) network, a thirdgeneration (3G) network, a code division multiple access (CDMA) network,etc.), a public land mobile network (PLMN), a local area network (LAN),a wide area network (WAN), a metropolitan area network (MAN), atelephone network (e.g., the Public Switched Telephone Network (PSTN)),a private network, an ad hoc network, an intranet, the Internet, a fiberoptic-based network, or the like, and/or a combination of these or othertypes of networks.

The number and arrangement of devices and networks shown in FIG. 1 areprovided as an example. In practice, there may be additional devicesand/or networks, fewer devices and/or networks, different devices and/ornetworks, or differently arranged devices and/or networks than thoseshown in FIG. 1. Furthermore, two or more devices shown in FIG. 1 may beimplemented within a single device, or a single device shown in FIG. 1may be implemented as multiple, distributed devices. Additionally, oralternatively, a set of devices (e.g., one or more devices) of theenvironment 100 may perform one or more functions described as beingperformed by another set of devices of the environment 100.

FIG. 2 is a block diagram of example components of one or more devicesof FIG. 1. The device 200 may correspond to the user device 110 and/orthe platform 120. As shown in FIG. 2, device 200 may include a bus 210,a processor 220, a memory 230, a storage component 240, an inputcomponent 250, an output component 260, and a communication interface270.

The bus 210 includes a component that permits communication among thecomponents of the device 200. The processor 220 is implemented inhardware, firmware, or a combination of hardware and software. Theprocessor 220 is a central processing unit (CPU), a graphics processingunit (GPU), an accelerated processing unit (APU), a microprocessor, amicrocontroller, a digital signal processor (DSP), a field-programmablegate array (FPGA), an application-specific integrated circuit (ASIC), oranother type of processing component. In some implementations, theprocessor 220 includes one or more processors capable of beingprogrammed to perform a function. The memory 230 includes a randomaccess memory (RAM), a read only memory (ROM), and/or another type ofdynamic or static storage device (e.g., a flash memory, a magneticmemory, and/or an optical memory) that stores information and/orinstructions for use by the processor 220.

The storage component 240 stores information and/or software related tothe operation and use of the device 200. For example, the storagecomponent 240 may include a hard disk (e.g., a magnetic disk, an opticaldisk, a magneto-optic disk, and/or a solid state disk), a compact disc(CD), a digital versatile disc (DVD), a floppy disk, a cartridge, amagnetic tape, and/or another type of non-transitory computer-readablemedium, along with a corresponding drive.

The input component 250 includes a component that permits the device 200to receive information, such as via user input (e.g., a touch screendisplay, a keyboard, a keypad, a mouse, a button, a switch, and/or amicrophone). Additionally. or alternatively, the input component 250 mayinclude a sensor for sensing information (e.g., a global positioningsystem (GPS) component, an accelerometer, a gyroscope, and/or anactuator). The output component 260 includes a component that providesoutput information from the device 200 (e.g., a display, a speaker,and/or one or more light-emitting diodes (LEDs)).

The communication interface 270 includes a transceiver-like component(e.g., a transceiver and/or a separate receiver and transmitter) thatenables the device 200 to communicate with other devices, such as via awired connection, a wireless connection, or a combination of wired andwireless connections. The communication interface 270 may permit thedevice 200 to receive information from another device and/or provideinformation to another device. For example, the communication interface270 may include an Ethernet interface, an optical interface, a coaxialinterface, an infrared interface, a radio frequency (RF) interface, auniversal serial bus (USB) interface, a Wi-Fi interface, a cellularnetwork interface, or the like.

The device 200 may perform one or more processes described herein. Thedevice 200 may perform these processes in response to the processor 220executing software instructions stored by a non-transitorycomputer-readable medium, such as the memory 230 and/or the storagecomponent 240. A computer-readable medium is defined herein as anon-transitory memory device. A memory device includes memory spacewithin a single physical storage device or memory space spread acrossmultiple physical storage devices.

Software instructions may be read into the memory 230 and/or the storagecomponent 240 from another computer-readable medium or from anotherdevice via the communication interface 270. When executed, softwareinstructions stored in the memory 230 and/or the storage component 240may cause the processor 220 to perform one or more processes describedherein. Additionally, or alternatively, hardwired circuitry may be usedin place of or in combination with software instructions to perform oneor more processes described herein. Thus, implementations describedherein are not limited to any specific combination of hardware circuitryand software.

The number and arrangement of components shown in FIG. 2 are provided asan example. In practice, the device 200 may include additionalcomponents, fewer components, different components, or differentlyarranged components than those shown in FIG. 2. Additionally, oralternatively, a set of components (e.g. one or more components) of thedevice 200 may perform one or more functions described as beingperformed by another set of components of the device 200.

FIG. 3 illustrates an example DASH client 300 that is configured toprocess Media Presentation Description (MPD) events 301, inband events302, and sparse timed metadata track events, according to embodiments ofthe present disclosure. The DASH client 300 can also be used forprocessing Common Media Application Format (CMAF) events. According toan embodiment, the DASH client 300 may be implemented by the user device100 of FIG. 1.

Events may be provided in order to signal aperiodic information to theDASH client 300 or to an application. Events may be timed (e.g. eachevent starts at a specific media presentation time and may have aduration). Events may include DASH specific signaling orapplication-specific events. DASH events may be identified by schemeidentifiers. For application specific events, a scheme identifier mayidentify the application such that the DASH client 300 can forward theevent to the proper application.

As shown in FIG. 3, the DASH client 300 may include an application 310,a DASH player's control, selection, & heuristic logic 315, a manifestparser 320, a DASH access API 325, an inband event & “moof” (moviefragment box) parser 330, a timed metadata track parser 335, an event &timed metadata buffer 340, a synchronizer & dispatcher 345, a fileformat parser 350, a media buffer 355, a media decoder 360, and an HTTPstack 370.

In FIG. 3, the broken lines represent control and/or synchronization;the regular, solid lines represent event and/or timed metadata flow; andthe bold, solid lines represent media data flow. The control and/orsynchronization may include, for example, a subscription function 306and an event/metadata API 307. The event and/or timed metadata flow mayinclude, for example, the MPD events 301, the inband events 302, thetimed metadata 303, and the DASH events 305. The media data flow mayinclude, for example, media segments 304.

The DASH client 300 may receive a manifest, such as MPDs, and mayprocess them. The manifest may describe a combination andsynchronization of independently packaged CMAF tracks grouped in CMAFswitching sets and selection sets to form a synchronized multimediapresentation. The manifest may provide the DASH client 300 withinformation to select, initialize, start align, and synchronize the CMAFtrack(s) to be played, and identify CMAF media objects (e.g. CMAFheaders, CMAF chunks, and CMAF fragments) as resources to access and topossibly download them. CMAF tracks and CMAF fragments may containsufficient information to enable decryption, decoding, and presentationscheduling. The manifest can also provide information on deliveryprotocol, network management, authorization, license acquisition, etc.,in addition to resource identification and presentation description. Themanifest can also signal that tracks conform to a CMAF media profile.

For reference, a CMAF fragment may be a media object that is encoded anddecoded. A CMAF fragment may include one or more pairs of a moviefragment box (‘moof’) and a media data box (‘mdat’). Each pair of ‘moof’and ‘mdat’ may be referred to as a CMAF chunk, and each CMAF chunk maycontain a consecutive subset of media samples belonging to a CMAFfragment.

A CMAF track may be a continuous sequence of one or more CMAF fragmentsin presentation order conforming to a CMAF media profile, and anassociated CMAF header. The CMAF header may contain a MovieBox that issufficient to process and present all CMAF fragments in the CMAF track.A CMAF track may be produced by an encoder and an ISOBMFF file packager,but may be made to be accessible in the form of CMAF addressable mediaobjects that can be references as resources defined by an external mediaapplication specification.

The DASH client 300 may request media segments based on describedaddresses in the manifest. The manifest may also describe metadatatracks. The DASH client 300 can also access the segment of metadatatracks, parse them, and send them to the application.

Also, of addresses for media segments, a DASH manifest may provideaddressed for Index segments. Each index segment may provide informationabout one segment duration and size. A Representation Index may providethe index information for all segments of a given representation.

According to embodiments, the manifest parser 320 may parse MPD events301 from the manifest, and append them to the event & timed metadatabuffer 340. Based on the MPD, the DASH client 300 may manage thefetching and parsing of Segments from the HTTP stack 370. The parsing ofthe Segments may be performed by the inband event & “moof” parser 330.The inband event & “moof” parser may parse media segments 304 from theSegments before appending them to the media buffer 355. The parsing bythe inband event & “moof” parser 330 may also include parsing inbandevents 302 and timed metadata 303 (e.g., timed metadata tracks) from theSegments. Also, the timed metadata track parser 335 may parse and appendhigh-level boxes such as event message boxes of the timed meta data 303and event message instance boxes of the timed meta data 303 to the event& timed metadata buffer 340.

The event & timed metadata buffer 340 may pass the events and timedmetadata samples to the synchronizer & dispatcher 345, which may bereferred to as an event & timed metadata synchronizer & dispatcherfunction.

The synchronizer & dispatcher 345 may dispatch DASH client 300 specificevents to the DASH player's control, selection, & heuristic logic 315.If the application 310 is subscribed to a specific event(s) and/or timedmetadata stream(s), the synchronizer & dispatcher 345 may dispatch thecorresponding event instances and/or timed metadata samples to theapplication 310 via the event/metadata API 307.

Embodiments may provide a method for signaling the relationship betweenevent instances in one event message track. Accordingly, embodiments mayextend the event message instance box to signal the more extendedrelationship between them.

In embodiments, the event message instance box can be extended to signala more extensive relationship between event instances. For example, inembodiments, the event message instance box may be used to signal that:

1. One event instance is an update of the previous one(s)

2. Timing change: the start and/or duration of the previous event ischanged.

3. The event is canceled and no further processing is necessary

4. Reserving bits for further extensions

In embodiments, and event message instance box may be extended asfollows:

aligned(8) class EventMessageInstanceBox    extends FullBox(‘emib’,version, flags = 0){   unsigned int(32) reserved = 0;   signed int(64) presentation_time_delta;   unsigned int(32) duration;   unsignedint(32) id;  unsigned int(32) update_id;   unsigned int(32) update_mode;  string scheme_id_uri;   string value;  unsigned int(8)message_data[ ];}

In the extended event message instance box as shown above:

-   -   update_id: may indicate that the new instance is an update of        the previous instance(s) with the identical value of this field.    -   update_mode: each value may define a specific relationship with        the previous instance. For example:        -   0: may indicate replacement, such that the new event            replaces the previous event        -   1: changes of timing, i.e. the start and/or of the event            have been updated.        -   2: cancelation: may indicate that this event instance            cancels the previous instance, i.e. previous instance does            not need to be processed.

Accordingly, embodiments, may provide a method of signaling a moreextended relationship, for example a relationship beyond equivalency,between the event instances in the event message track, wherein one ormore event instances may be linked together using a unique newidentifier for updating, and another field may show the relationshipincluding replacement, change of timing, and cancelation, wherein whenan event message instance is detected that is an update to the previousinstance(s), the client may only process the updated instance or correctthe previously processed ones.

FIG. 4 is a flow chart of an example process 400 for managing a mediastreaming system that includes the DASH client 300. In someimplementations, one or more process blocks of FIG. 4 may be performedby user device 441. In some implementations, one or more process blocksof FIG. 4 may be performed by another device or a group of devicesseparate from or including user device 110, such as platform 120.

As shown in FIG. 4, process 400 may include obtaining an event messagetrack including a plurality of event message instance boxes, the eventmessage track configured to be processed by a Dynamic Adaptive Streamingover HyperText Transfer Protocol (DASH) client for displaying mediacontent (block 410).

As further shown in FIG. 4, process 400 may include obtaining a firstevent message instance box included in the event message track (block420).

As further shown in FIG. 4, process 400 may include obtaining a secondevent message instance box included in the event message track, whereinthe second event message instance box includes first informationidentifying the first event message instance box, and second informationspecifying a relationship between the first event message instance boxand the second event message instance box (block 430).

As further shown in FIG. 4, process 400 may include modifying the firstevent message instance box based on the first information and the secondinformation (block 440).

As further shown in FIG. 4, process 400 may include providing the eventmessage track to the DASH client or displaying media content based onthe event message track (block 440).

In embodiments, the first event message instance box may include anidentifier, and the first information may include an update identifier,and process 400 may further include determining that the first eventmessage instance box is related to the second event message instance boxbased on a value of the identifier being equal to a value of the updateidentifier.

In embodiments, the second information may include a value indicating atype of the relationship between the first event message instance boxand the second event message instance box.

In embodiments, based on the value being a first value, the secondinformation indicates that the relationship has a first relationshiptype, based on the value being a second value, the second informationindicates that the relationship has a second relationship type, andbased on the value being a third value, the second information indicatesthat the relationship has a third relationship type.

In embodiments, the first relationship type may be a replacementrelationship, and based on the value being the first value, themodifying of the first event message instance box may include replacingthe first event message instance box in the event message track with thesecond event message instance box.

In embodiments, the second relationship type may be a timing changerelationship, and based on the value being the second value, themodifying of the first event message instance box may include changingat least one of a start time corresponding to the first event messageinstance box, or an end time corresponding to the first event messageinstance box.

In embodiments, the third relationship type may be a cancelationrelationship, and based on the value being the third value, themodifying of the first event message instance box may include cancelingthe first event message instance box from the event message track.

Although FIG. 4 shows example blocks of process 400, in someimplementations, process 400 may include additional blocks, fewerblocks, different blocks, or differently arranged blocks than thosedepicted in FIG. 4. Additionally, or alternatively, two or more of theblocks of process 400 may be performed in parallel.

With reference to FIG. 5, computer code 500 according to embodiments isdescribed. The computer code 500 may performed by a media streamingsystem that includes the DASH client 300. For example, the mediastreaming system may be implemented by the environment 100 describedwith respect to FIG. 1. The media streaming system may comprise memoryconfigured to store computer code 500, and at least one processorconfigured to access the computer code 500 and operate as instructed bythe computer code 500. The computer code 500 may be distributed amongstmemory of different components of the media streaming system (e.g.servers, clients, etc.) and may be configured to cause the at least oneprocessor of the specific component to perform any number of theirfunctions, including the functions described in the present disclosure.For example, the computer code 500 may comprise any number of firstobtaining code 510, second obtaining code 520, third obtaining code 530,modifying code 540, and providing code 550.

In embodiments, the first obtaining code 510, second obtaining code 520,third obtaining code 530, modifying code 540, and providing code 550 maybe configured to cause the media streaming system that includes the DASHclient 300 to perform the aspects of the process described above withreference to FIG. 4, respectively.

The embodiments of the present disclosure may be used separately orcombined in any order. Further, each of the methods, servers, andclients may be implemented by processing circuitry (e.g., one or moreprocessors or one or more integrated circuits). In one example, the oneor more processors execute a program that is stored in a non-transitorycomputer-readable medium.

The foregoing disclosure provides illustration and description, but isnot intended to be exhaustive or to limit the implementations to theprecise form disclosed. Modifications and variations are possible inlight of the above disclosure or may be acquired from practice of theimplementations.

It will be apparent that systems and/or methods, described herein, maybe implemented in different forms of hardware, firmware, or acombination of hardware and software. The actual specialized controlhardware or software code used to implement these systems and/or methodsis not limiting of the implementations. Thus, it should be understoodthat software and hardware may be designed to implement the systemsand/or methods based on the description herein.

Even though particular combinations of features are recited in theclaims and/or disclosed in the specification, these combinations are notintended to limit the disclosure of possible implementations. In fact,many of these features may be combined in ways not specifically recitedin the claims and/or disclosed in the specification. Although eachdependent claim listed below may directly depend on only one claim, thedisclosure of possible implementations includes each dependent claim incombination with every other claim in the claim set.

No element, act, or instruction used herein should be construed ascritical or essential unless explicitly described as such. Also, as usedherein, the articles “a” and “an” are intended to include one or moreitems, and may be used interchangeably with “one or more.” Furthermore,as used herein, the term “set” is intended to include one or more items(e.g., related items, unrelated items, a combination of related andunrelated items, etc.), and may be used interchangeably with “one ormore.” Where only one item is intended, the term “one” or similarlanguage is used. Also, as used herein, the terms “has,” “have,”“having,” or the like are intended to be open-ended terms. Further, thephrase “based on” is intended to mean “based, at least in part, on”unless explicitly stated otherwise.

What is claimed is:
 1. A method performed by at least one processor, themethod comprising: obtaining an event message track including aplurality of event message instance boxes, the event message trackconfigured to be processed by a Dynamic Adaptive Streaming overHyperText Transfer Protocol (DASH) client for displaying media content,the plurality of event message instance boxes corresponding to aplurality of events comprising one or more of Media PresentationDescription (MPD) events, inband events, timed metadata, Common MediaApplication Format (CMAF) events, and DASH events; obtaining a firstevent message instance box included in the event message track;obtaining a second event message instance box included in the eventmessage track, wherein the second event message instance box includesfirst information identifying the first event message instance box, andsecond information specifying a relationship between the first eventmessage instance box and the second event message instance box;modifying the first event message instance box based on the firstinformation and the second information; and providing the event messagetrack to the DASH client or displaying media content based on the eventmessage track.
 2. The method of claim 1, the first event messageinstance box comprises an identifier, wherein the first informationcomprises an update identifier, and wherein the method further comprisesdetermining that the first event message instance box is related to thesecond event message instance box based on a value of the identifierbeing equal to a value of the update identifier.
 3. The method of claim1, wherein the second information includes a value indicating a type ofthe relationship between the first event message instance box and thesecond event message instance box.
 4. The method of claim 3, whereinbased on the value being a first value, the second information indicatesthat the relationship has a first relationship type, wherein based onthe value being a second value, the second information indicates thatthe relationship has a second relationship type, and wherein based onthe value being a third value, the second information indicates that therelationship has a third relationship type.
 5. The method of claim 4,wherein the first relationship type is a replacement relationship, andwherein, based on the value being the first value, the modifying of thefirst event message instance box comprises replacing the first eventmessage instance box in the event message track with the second eventmessage instance box.
 6. The method of claim 4, wherein the secondrelationship type is a timing change relationship, and wherein, based onthe value being the second value, the modifying of the first eventmessage instance box comprises changing at least one of a start timecorresponding to the first event message instance box, or an end timecorresponding to the first event message instance box.
 7. The method ofclaim 4, wherein the third relationship type is a cancelationrelationship, and wherein, based on the value being the third value, themodifying of the first event message instance box comprises cancelingthe first event message instance box from the event message track.
 8. Adevice comprising: at least one memory storing program code; and atleast one processor configured to read the program code and operate asinstructed by the program code, the program code including: firstobtaining code configured to cause the at least one processor to obtainan event message track including a plurality of event message instanceboxes, the event message track configured to be processed by a DynamicAdaptive Streaming over HyperText Transfer Protocol (DASH) client fordisplaying media content, the plurality of event message instance boxescorresponding to a plurality of events comprising one or more of MediaPresentation Description (MPD) events, inband events, timed metadata,Common Media Application Format (CMAF) events, and DASH events; secondobtaining code configured to cause the at least one processor to obtaina first event message instance box included in the event message track;third obtaining code configured to cause the at least one processor toobtain a second event message instance box included in the event messagetrack, wherein the second event message instance box includes firstinformation identifying the first event message instance box, and secondinformation specifying a relationship between the first event messageinstance box and the second event message instance box; modifying codeconfigured to cause the at least one processor to modify the first eventmessage instance box based on the first information and the secondinformation; and providing code configured to cause the at least oneprocessor to provide the event message track to the DASH client ordisplay media content based on the event message track.
 9. The device ofclaim 8, the first event message instance box comprises an identifier,wherein the first information comprises an update identifier, andwherein the modifying code is further configured to cause the at leastone processor to determine that the first event message instance box isrelated to the second event message instance box based on a value of theidentifier being equal to a value of the update identifier.
 10. Thedevice of claim 8, wherein the second information includes a valueindicating a type of the relationship between the first event messageinstance box and the second event message instance box.
 11. The deviceof claim 8, wherein based on the value being a first value, the secondinformation indicates that the relationship has a first relationshiptype, wherein based on the value being a second value, the secondinformation indicates that the relationship has a second relationshiptype, and wherein based on the value being a third value, the secondinformation indicates that the relationship has a third relationshiptype.
 12. The device of claim 11, wherein the first relationship type isa replacement relationship, and wherein, based on the value being thefirst value, the modifying code is further configured to cause the atleast one processor to replace the first event message instance box inthe event message track with the second event message instance box. 13.The device of claim 11, wherein the second relationship type is a timingchange relationship, and wherein, based on the value being the secondvalue, the modifying code is further configured to cause the at leastone processor to change at least one of a start time corresponding tothe first event message instance box, or an end time corresponding tothe first event message instance box.
 14. The device of claim 11,wherein the third relationship type is a cancelation relationship, andwherein, based on the value being the third value, the modifying code isfurther configured to cause the at least one processor to cancel thefirst event message instance box from the event message track.
 15. Anon-transitory computer-readable medium storing instructions that, whenexecuted by at least one processor, cause the at least one processor to:obtain an event message track including a plurality of event messageinstance boxes, the event message track configured to be processed by aDynamic Adaptive Streaming over HyperText Transfer Protocol (DASH)client for displaying media content, the plurality of event messageinstance boxes corresponding to a plurality of events comprising one ormore of Media Presentation Description (MPD) events, inband events,timed metadata, Common Media Application Format (CMAF) events, and DASHevents; obtain a first event message instance box included in the eventmessage track; obtain a second event message instance box included inthe event message track, wherein the second event message instance boxincludes first information identifying the first event message instancebox, and second information specifying a relationship between the firstevent message instance box and the second event message instance box;modify the first event message instance box based on the firstinformation and the second information; and provide the event messagetrack to the DASH client or display media content based on the eventmessage track.
 16. The non-transitory computer-readable medium of claim15, wherein the second information includes a value indicating a type ofthe relationship between the first event message instance box and thesecond event message instance box.
 17. The non-transitorycomputer-readable medium of claim 16, wherein based on the value being afirst value, the second information indicates that the relationship hasa first relationship type, wherein based on the value being a secondvalue, the second information indicates that the relationship has asecond relationship type, and wherein based on the value being a thirdvalue, the second information indicates that the relationship has athird relationship type.
 18. The non-transitory computer-readable mediumof claim 17, wherein the first relationship type is a replacementrelationship, and wherein, based on the value being the first value, themodifying of the first event message instance box comprises replacingthe first event message instance box in the event message track with thesecond event message instance box.
 19. The non-transitorycomputer-readable medium of claim 17, wherein the second relationshiptype is a timing change relationship, and wherein, based on the valuebeing the second value, the modifying of the first event messageinstance box comprises changing at least one of a start timecorresponding to the first event message instance box, or an end timecorresponding to the first event message instance box.
 20. Thenon-transitory computer-readable medium of claim 17, wherein the thirdrelationship type is a cancelation relationship, and wherein, based onthe value being the third value, the modifying of the first eventmessage instance box comprises canceling the first event messageinstance box from the event message track.